Strap applying tool

ABSTRACT

A tool is disclosed for applying and tightening a strap around a bundle of articles such as electrical wires or cables. When the strap has been tensioned to a predetermined value, the tool is operative to either release or sever the strap at the discretion of the operator.

United States Patent [1 1 Benfer [451 Aug. 20, 1974 STRAP APPLYING TOOL [75] Inventor: David Van Dike Benfer, Marysville,

3,610,296 10/1971 Kabel 140/93.2 3,735,784 5/1973 Obuch et al. 140/93.2 3,752,199 8/1973 Fekete 140/93.2 3,782,426 l/l974 Morgan et a1. 140/93.2

Primary Examiner-Lowell A. Larson Attorney, Agent, or FirmWilliam .l. Keating; Frederick W. Raring; Jay L. Seitchik [52] US. Cl. l40/93.2, 140/123.6 [57] ABSTRACT [51] Int. Cl B211 9/02 58 Field of Search 140/93, 93 A, 93.2, 123.5, A dlsclosed ,aPPlYmg i Strap 140M236 around a bundle of articles such as electrical wires or cables. When the strap has been tensioned to a prede- [56] References Cited termined value, the tool is operative to either release UNITED STATES PATENTS or sever the strap at the discretion of the operator.

3,168,119 2/1965 Schwester, et al 140/149 7 Claims, 8 Drawing Figures 7 70 1 F 1 e l aw i 0r T hit-3?: I"! i" Pmmmwsz 3.630.263

sum aor s PAIENIEUMIEZOIBH 3.930.263

SHEET 50F 5 I STRAP APPLYING TOOL SUMMARY OF THE INVENTION This invention relates to the art of hand tools and more particularly to such tools as are useful in applying straps around a bundle of wire or cable and subsequently tightening such straps to a predetermined value. The tool is designed so that it can be operated in a cut or no-cut mode whereby the operator can alter the functioning of the tool to suit his immediate needs.

Tools are known for tightening a strap around a bun dle of wires and for subsequently tightening such straps to a predetermined value and automatically severing the excess strap. Examples of such tools are shown in US. Pat. Nos. 3,610,296; 3,444,815; and 'Re26,492. All of the tools described in these patents are similar in that they perform the tightening and automatic cut off functions. After the excess strap has been cut off the operator is no longer able to perform any subsequent tightening of the strap. This has the disadvantage in that there are many instances where the bundle of wires is manipulated after the strap is applied and the wires change their orientation within the bundle to the extent that the strap is no longer in a tight condition. Another problem is that one or more wires of the bundle may be removed, in which case the strap is again left in an untightened condition around the bundle. When this occurs, the operator has no choice but to apply a new strap to the bundle, resulting in a waste of material and cost in that two straps are being employed to perform the function of one.

The tool of the instant invention is designed to overcome this problem in that the operator can tighten a strap to a predetermined tension and the tool can then be removed from the strap without effecting a severing operation. At a later time the operator, with the same tool, can reinsert the strap end into the tool and by the simple movement of a button, can alter the operation of the tool into a cutting mode whereby the strap will be once again tightened to a predetermined value and automatically the excess strap will be severed.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, in which like reference numerals refer to like parts:

FIG. 1 is a side elevational view of the tool of the present invention showing the parts in their rest conditron;

FIG. 2 is a view similar to FIG. 1 and showing the tool during a tensioning operation;

FIG. 3 is a view similar to FIG. 1 and showing the tool in its position when the desired tension is in the strap;

FIG. 4 is a view similar to FIG. 1 showing the tool in its cutting position;

FIG. 5 is an exploded perspective view showing the various parts of the tool;

FIG. 6 is an exploded perspective view showing further details of the internal mechanism of the tool of FIG. 5;

FIG. 7 is a fragmentary cross-sectional view taken along the line 7-7 of FIG. 1; and

FIG. 8 is a fragmentary view showing the mechanism for controlling the cutting function of the tool.

DETAILED DESCRIPTION The tool of the present invention is best seen in FIGS. 1-5 and is indicated generally at 10. The tool 10 comprises a pair of casings l2 and 14 which join together to give the tool its overall configuration and which generally enclose the operating mechanism indicated at 16.

The casings l2 and 14 can be best seen in FIG. 5, casing 14 being omitted from the majority of the other fig ures in order to expose the working parts of the tool. The configuration of. the tool resembles that of a hand pistol, with casing 12 having a forward nose portion 18, a rearward portion 20, and a handle or grip portion 22. The casing 14 has a handle or grip portion 24 and an upper portion 26 which is somewhat smaller than the upper portion of casing 12 whereby the forward end of casing 14 terminates somewhat rearwardly of the nose portion 18 of casing 12. The two casings are joined together by suitable pin means at various locations along the casings.

The mechanism 16 generally comprises an operating lever 28 connected by a linkage, to be described, to a gripper mechanism 30 and a cut off mechanism 32.

Various portions of the tool will now be described with reference to FIGS. 1 and 5, FIG. 1 showing the tool in its rest condition. The operating lever 28 is connected by pin 34 to casings l2 and 14 for pivotal movement about the pin. The lever 28 is shown in FIG. 1 in its forward most position. An operator would move lever 28 rightward as seen in FIG. 1 causing the lever to rotate about pin 34 in a counterclockwise direction in order to operate the tool, as will become more fully apparent hereinbelow. The operating lever 28 is connected by pin 36 to a pressure release lever 38. The pressure release lever is of bifurcated configuration as best shown in FIG. 6. The lever 38 is located between a pair of walls 40 and 42 formed along the upper portion of operating lever 28. A slot 44 is disposed in the operating lever with pin 36 extending through the slot. The slot 44 is formed in both walls 40 and 42 although only one is shown in the drawings.

The pressure release lever 38 is pinned at 46 to a tension spring 48. The upper end of the tension spring is wrapped around the pin 46 and the ends of pin 46 are disposed in nesting portions 50 disposed along the inner surface of the casings l2 and 14. The nest 50 permits limited vertical movement of pin 46 and thus pressure release lever 38. The tension spring 48, however, normally maintains pin 46 at the bottom of nest 50 whereby the pressure release lever 38 oscillates about the pin 46. It is apparent from the drawings that movement of the operating lever 28 in a rightward or counterclockwise direction causes the pressure release lever 38 to oscillate in a clockwise direction about pin 46 by means of the pin 36 which connects the levers 28 and 38.

The lower portion of tension spring 48 is connected to a tension adjustment mechanism 52. Mechanism 52 comprises a screw member 54 which is threadably received in the casings 12 and 14 and which is internally threaded to receive a second screw member 56 with the member 56 being directly connected to the spring 48. The screw members 54 and 56 are oppositely threaded whereby rotation of member 54 by an operator will cause the member 56 to move axially at twice the rate of member 54 thus providing a rapid means of adjusting tension in the spring 48. The upper portion of screw member 56 is provided with an indicating line 58 which is visible through a slot 60 formed in the grip portion of casing 14. Adjacent slot 60 is a scale and numerical indicia whereby an operator can determine the relative position of screw member 56 and indicating line 58 to thereby determine the degree of tension set in the spring 48. It will be apparent that downward movement of the tension adjustment mechanism 52 as seen in FIG. 1 will cause the spring 48 to be stretched thereby increasing the tension in the spring and increasing the force which urges the pin 46 and pressure release lever 38 into their lowermost position as shown in FIG. 1.

The gripper mechanism 30 comprises a drawbar 62 which is generally elongated and is mounted for reciprocating movement within the casing 12. The drawbar is generally guided in its movement by means of a shoulder 64 on casing 12 and by an oppositely disposed shoulder 66 as best seen in FIG. 5. The drawbar is also guided by means of a pin 68 which is fixed to the drawbar and which reciprocates within a slot 70 disposed in casing 12. The forward end of drawbar 62 carries a gripper 72 which cooperates with a backup surface 74 for gripping a strap therebetween. The gripper 72 is pivotally mounted to drawbar 62 by pin means 76 and is normally biased by a spring (not shown) in a counterclockwise direction. When the drawbar is in its forward most position such as shown in FIG. 1, the gripper 72 is cammed clockwise to a non-gripping position by engagement with a plate 78 secured to casing 12. In the position shown in FIG. 1 the gripper and backup surface 72 and 74 respectively are spaced apart sufficiently to permit a strap to enter therebetween through a slot indicated at 80. The gripper 72 will normally move under the influence of its biasing spring into engagement with a strap disposed between the gripper and the backup surface 74 such as is shown in FIG. 2. Gripper 72 is an over center mechanism whereby a substantial gripping force is exerted on the strap. The details of gripper 72 and its cooperation with the backup surface 74 are well known in the art.

The rearward portion of mechanism 30 comprises an enlarged section 82 having disposed therein a pair of elongated slots 84 and 86. The slot 84 accomodates the pin 34 connecting the operating lever 28 to the casings whereby the pin 34 will not interfere with the reciprocating movement of the drawbar. The slot 86 has a forward depression 88 within which normally rests a roller 90 disposed around a pin 92. The pin 92 connects the drawbar to the upper portion of pressure release lever 38, the pin 92 extending through apertures 94 in the release lever. The roller 90 is normally maintained in the depression 88 by means of the tension exerted on the release lever 38 by the tension spring 48. The amount of force holding the roller in the depression is governed by the setting of tension adjustment mechanism 52.

At the rearward portion of casing 12 there is disposed a stop surface 96 which is positioned to engage a shoulder 98 formed along the upper portion of release lever 38. Since the release lever is bifurcated at its upper end, there are in reality two shoulders 98 one of which is positioned to contact the stop surface 96 on casing 12 while the other stop shoulder is positioned to engage a similar stop surface (not shown) disposed within the upper portion of casing 14. It can also be seen in FIG. 1 that the operating lever 28 is biased in a forward or clockwise direction by means of a spring 100 acting between the rear portion of the casings and a pin I02 extending between the walls 40 and 42 of the operating lever.

The cutoff mechanism 32 comprises a cutoff lever 104 secured between casings 12 and 14 by means of a pin 106 with the lever being capable of oscillating movement about such pin. The rearward portion of the lever 104 carries a roller 108 positioned to be engageable by a cutoff cam 110 formed along the forward edge of wall 42 of the operating lever. The cutoff lever 104 is normally biased in a counterclockwise direction by spring means 112 and is limited in the counterclockwise direction by pin 114 fixed to the casing. The forward end of cutoff lever 104 carries a cutting blade 1 16 which is movable across slot 80 into contact with an anvil 117 to sever a strap disposed within the slot.

In FIG. 8 there is shown a selector 118 which is disposed along the outer surface of casing 14. The selector consists of a finger gripping surface 120 movable between positions which are indicated on the casing as being YES or NO with regard to the desired mode of operation of the tool. The YES and NO indicia indicate whether or not the tool is in a cutting or non-cutting mode of operation. The finger grip 120 is attached to a pin 12.2 which extends through an opening 124 formed in the wall 42 of the operating lever. The opening 124 generally consists of a pair of joined slots 126 and 128 within which the pin 122 may travel. In FIG. 1 the selector 118 is shown in a NO CUT position which corresponds to the pin 122 being in its leftward position. With the pin 122 so disposed, movement of the operating lever 28 is permitted by means of the slot 126 forming a clearance passageway for the pin 122. The extent of counterclockwise or rightward movement of the operating lever 28 is limited by engagement of the pin 122 with the upper end of the slot 126 such as is shown when the tool is in the position of FIG. 2. If the selector 118 is moved to a YES CUT condition, which corresponds to the pin 122 being in its rightward position such as shown in phantom in FIG. 2 and in solid lines in FIGS. 3 and 4, the opening 124 in the operating lever no longer limits the movement of the lever since the pin is now operating within the slot 128, such slot being of greater extent than the slot 126, all as will become more apparent when the operation of the tool is described.

It can be seen from FIG. 2 that the extent of travel of the operating lever 28 is not sufficient to permit the cutoff cam 110 to contact roller 108 and therefore repeated movement of the operating lever is ineffective to operate the cutoff lever 1.04 and thus the shear blade 116.

The operation of the tool described above will now be set forth with reference to FIGS. 1-4, which figures set forth the various operating stages of the tool. Beginning with FIG. 1 the various parts of the tool are shown in their rest condition. It can be seen that the pin 122 is in its leftward position so we shall assume that the operator has chosen initially to place the tool in a NO CUT operating mode. The tension adjustment mechanism 52 will be set to whatever tension is desired by the operator to be applied to the strap which will be secured around a bundle.

In FIG. 2 there is shown a bundle of wires or cables 130 with a strap 132 disposed therearound. The strap may be of many various configurations known in the art, the one shown in the drawing being of the type wherein a head portion 134 is molded at one end of a generally elongated strap with the opposite tail end 136 of the strap being disposed around the bundle and subsequently threaded through the head 134. The tail 136 is then inserted into the slot 80 located at the nose portion of the tool and the strap is threaded between the gripper 72 and backup surface 74 such as is shown in FIG. 2 of the drawings. With the strap located as described above the operator will move lever 28 to the right with a squeezing motion whereby the lever will pivot around the point 34 and will cause the pressure release lever 38 to pivot in a clockwise direction thus driving the drawbar 62 rightward as indicated by the arrow 138 in FIG. 2. The roller 90 is maintained in the depression 88 in the drawbar by means of the tension within the spring 48. The operator will alternatively squeeze and release the lever 28 as many times as is necessary to reach the desired tension of the strap around the bundle 130. Each time the lever 28 is released the spring 100 causes the lever to return to its forward most position and in doing so the drawbar 62 is moved to its forward most or leftward position.

When the desired tension in strap 132 has been reached, the force exerted on the drawbar 62 by the strap will exceed the force exerted by spring 48 holding roller 90 in depression 88. This will cause the roller 90 to ride out of the depression 88 in the manner shown in FIG. 3. When this is achieved, the linkage between the lever 28 and the drawbar 62 becomes disconnected so that further movement of lever 28 is not operative to move drawbar 62 but rather the roller 90 will simply move along the slot 86 at the rearward portion of the drawbar. It will also be evident that this release of the drawbar causes the tension in the strap between the head 134 and the gripper 72 to be substantially zero. If the tool is in the NO CUT condition the cutoff mechanism cannot be operated and therefore the operator can simply remove the tool from the strap leaving the strap tightened around the bundle and having the tail 136 remaining as an integral part of the strap. If, however, the operator desires to cut off the tail of the strap, then the selector 118 is moved to the right into the YES CUT condition and the pin 122 is in the position as shown in FIG. 3 of the drawings. In this position the pin moves in the larger slot 128, such slot permitting over travel of lever 28 to the position shown in FIG. 4 whereby the cutoff cam 110 will engage the roller 108 to thereby oscillate the lever 104 in a clockwise direction thus moving the cutting blade 116 across slot 80 against anvil 117 to effect severing of the bundle strap. Since severing occurs when the strap end is not under tension, a smoother cut is achieved than with many of the prior art devices. It should be noted that if the selector 118 is initially set to the YES CUT condition the several strokes of lever 28 are limited by engagement of the shoulders 98 on the pressure release lever with the stop surfaces 96 on the casings l2 and 14. Therefore it is not possible to sever the strap until the proper tension has been reached in the strap since the lever 28 cannot over travel to the position of FIG. 4.

It can thus be seen that a tool has been described which is capable of either tightening a strap around a bundle to a predetermined tension and thereafter releasing the strap without effecting a severing operation or the tool can'be operated in a manner whereby the strap is tightened to a predetermined tension and thereafter the handle may be moved to an over travel position to thus effect severing of the excess tail portion of the strap. This is possible because of the selector 1'18 and also because of the fact that the tension on the strap beyond the head 134 is released when the predetermined tenison is reached. If the tension was not released then the operator would have difficulty removing the tool from the strap even though no severing had occurred.

The above description sets forth a preferred embodiment of the invention. Various modifications will be apparent to those skilled in the art upon a reading of the above description and such modifications are inteded to be included within the scope of this invention.

What is claimed is:

1. A tool for applying a strap having a lock portion and end portion to a bundle of wires or similar object, said tool comprising:

a tool body having a generally pistol-like configuration with a nose portion, a rear portion, and a handle portion;

an opening in said body nose portion communicating with an interior passageway in said body for receiving the end portion of a strap;

a gripping mechanism reciprocable along said body for engaging said strap end portion and pulling said end towards said body rear portion to thereby place said strap end portion under tension;

an operating lever mounted on said body for movement relative thereto and having a normal working stroke between first and second positions;

a tension release mechanism for operatively connecting said operating lever to said gripping mechanism when the tension in said strap end portion is below a predetermined value, and for operatively disconnecting said operating lever from said gripping mechanism when the tension in said strap end portion reaches said predetermined value;

a cutoff member mounted on said body for movement relative thereto and having a blade means disposed adjacent said opening in said body nose portion, said cutoff member being inoperative during the normal working stroke of said operating lever;

selector means located on said body and movable between first and second settings;

means for limiting the movement of said operating lever to its normal working stroke when said selector means is at said first setting;

and means for permitting movement of said operating lever beyond its normal working stroke to a third position when said selector means is at said second setting, said operating lever having means for actuating said cutoff member when moved to said third position; whereby said tool is operative to apply a strap to a predetermined tension when said selector means is atsaid first setting, and is operative to apply a strap to a predetermined tension and to sever the strap end portion when said selector means is at said second setting.

2. A tool for applying a strap as set forth in claim 1 wherein said gripping mechanism has an elongated slot formed therein, a depression formed in said slot, and wherein said tension release mechanism comprises roller means normally positioned within said depression, said roller means being movable out of said depression and into said slot upon the tension in said strap reaching said predetermined value.

3. A tool for applying a strap as set forth in claim 2 wherein said tension release mechanism further comprises shoulder means positioned for engaging stop means located on said tool body for limiting movement of said tension release mechanism when the tension in said strap is below said predetermined value.

4. A tool for applying a strap as set forth in claim 1 wherein said cutoff member has roller means mounted thereon and wherein said operating lever includes cam means for engaging said roller means when the operating lever is moved from its second position to its third position to thereby move said cutoff member and said blade means to effect a severing operation.

5. A tool for applying a strap as set forth in claim 4 7. A tool for applying a strap as set forth in claim 4 further comprising anvil means disposed opposite said blade means for cooperation therewith to effect the severing operation. 

1. A tool for applying a strap having a lock portion and end portion to a bundle of wires or similar object, said tool comprising: a tool body having a generally pistol-like configuration with a nose portion, a rear portion, and a handle portion; an opening in said body nose portion communicating with an interior passageway in said body for receiving the end portion of a strap; a gripping mechanism reciprocable along said body for engaging said strap end portion and pulling said end towards said body rear portion to thereby place said strap end portion under tension; an operating lever mounted on said body for movement relative thereto and having a normal working stroke between first and second positions; a tension release mechanism for operatively connecting said operating lever to said gripping mechanism when the tension in said strap end portion is below a predetermined value, and for operatively disconnecting said operating lever from said gripping mechanism when the tension in said strap end portion reaches said predetermined value; a cutoff member mounted on said body for movement relative thereto and having a blade means disposed adjacent said opening in said body nose portion, said cutoff member being inoperative during the normal working stroke of said operating lever; selector means located on said body and movable between first and second settings; means for limiting the movement of said operating lever to its normal working stroke when said selector means is at said first setting; and means for permitting movement of said operating lever beyond its normal working stroke to a third position when said selector means is at said second setting, said operating lever having means for actuating said cutoff member when moved to said third position; whereby said tool is operative to apply a strap to a predetermined tension when said selector means is at said first setting, and is operative to apply a strap to a predetermined tension and to sever the strap end portion when said selector means is at said second setting.
 2. A tool for applying a strap as set forth in claim 1 wherein said gripping mechanism has an elongated slot formed therein, a depression formed in said slot, and wherein said tension release mechanism comprises roller means normally positioned within said depression, said roller means being movable out of said depression and into said slot upon the tension in said strap reaching said predetermined value.
 3. A tool for applying a strap as set forth in claim 2 wherein said tension release mechanism further comprises shoulder means positioned for engaging stop means located on said tool body for limiting movement of said tension release mechanism when the tension in said strap is below said predetermined value.
 4. A tool for applying a strap as set forth in claim 1 wherein said cutoff member has roller means mounted thereon and wherein said operating lever includes cam means for engaging said roller means when the operating lever is moved from its second position to its third position to thereby move said cutoff member and said blade means to effect a severing operation.
 5. A tool for applying a strap as set forth in claim 4 wherein said operating lever includes a pair of joined slots and wherein said selector means includes a member disposed for movement within one of said pair of slots.
 6. A tool for applying a strap as set forth in claim 5 wherein one slot of said pair of slots is shorter than the second slot of said pair, said one slot being operative to limit movement of said operating lever to its normal working stroke whereas said second slot permits movement of said operating lever to its said third position.
 7. A tool for applying a strap as set forth in claim 4 further comprising anvil means disposed opposite said blade means for cooperation therewith to effect the severing operation. 